Brush retractors



Feb. 12, 1957 HOY 2,780,949

' BRUSH RETRAC'I'ORS Filed Aug. 18, 1953 IN V EN TOR.

32 THOMAS H. HOY

ATTORNEY BRUSH RETRACTORS Thomas H. Hoy, Jenkintown, Pa.

Application August 18, 1953, Serial No. 374,892

4 Claims. (Cl. 81-3) This invention relates to brush retractors, that is to devices for retracting the spring tensioned brushes of electrical apparatus, such as generators and starting motors, and particularly those used in the electrical systems of automobiles.

When an automobile generator or starting motor is taken apart, for the purpose of repairs, .lhere is always considerable difficulty in reassembling the same by reason of the necessity to retract the brushes, against the tension of their respective springs, a suificient distance to enable the brushes to clear the end of the commutator when the armature is replaced.

Numerous efforts have been made to provide means for overcoming this difiiculty but none of the devices heretofore suggested for this purpose have proved entirely satisfactory.

The principal object of the present invention is to pro vide a device, of a relatively inexpensive character, which may be used for the purpose of retracting the generator brushes, and for holding the same a sufiicient distance from the axis of the rotation of the armature so that the brushes will be held away from the commutator as the parts are being assembled.

The nature and characteristic features of the present invention will be more readily understood from the following description, taken in connection with the accompanying drawing forming part hereof, in which:

Figure 1 is a sectional view of one end of a generator, of a type commonly used in automobiles and the like for the purpose of supplying electrical current to the ignition system for recharging the storage battery forming part of the electrical system, certain of the internal parts being shown in elevation, and having a device embodying the main features of the present invention shown in connection therewith;

Fig. 2 is an external elevational view of the parts shown in Fig. 1;

Fig. 3 is a transverse sectional view taken approximately on the line 3 53 of Fig. 1; and

Pig. 4 is a perspective view of one of the hook-like brush retractor devices employed.

It should, of course, be understood that the description and drawing herein are illustrative merely, and that various modifications and changes may be made in the devices shown without departing from the spirit of the invention.

Refer-ring to the drawing, there is therein shown one end of a typical and common form of generator, of the type commonly used in automobiles as a part of the ignition system thereof and for recharging the storage battery.

In such generators there is provided an armature of an ordinary type and a commutator 11 associated therewith, the same being mounted on a shaft 12, the end of which is journaled in a suitable bearing 13 provided in the center of the head member 14 0f the generator. The head member 14 is mounted on the end of the casing 15 nited States Patent 0 2 of the generator. At the end of the casing 15, adjacent the head member 14 there its provided a plurality of open lugs 16, one for each of the brushes 17 so as to permit access thereto for making certain minor adjustments which may be done without dismantling the generator.

The openings 16 are ordinarily closed by means of a band encircling that portion of the generator casing 15 which, however, is not shown, as the same forms no part of the present invention, and which is customarily removed whenever required to permit access to the parts of the brush assembly.

Each of the brushes 17 of the generator is mounted on the end of a carrier arm 18 which is pivotally mounted on :a pin 19 extending from the head member 14. A spring 20 is coiled around the pin 19 and has one end bearing against a part of the outer end portion of the carrier arm 1.8 to which the brush 17 is attached. The other end of the spring 20 is anchored on another pin 21 extending from the head member 14.

The springs 20 normally impel the brushes 17 carried by the carrier arms 18 toward the surface of the commutator 11 and there is sumcient freedom of movement of the brushes inwardly so that the same will ordinarily be positioned within the normal location of the surface of the commutator whenever the head member 14 carrying the brushes is removed from the end of the casing 15, or in the alternative, when the armature is removed from the casing.

The device of the present invention comprises, for each of the brush units, a retractor member comprising primanily a rod 30 having one end bent over substantially at right angles, as at 31, to provide a book which is adapted to engage a portion of one of the brush carrier arms 18.

There is also provided a supporting device which may be formed from heavy sheet metal and which comprises an annular part 40 and an ofiset central portion 41 which is provided for the purpose of clearing the projecting portion of the bearing 13 of the head member 14 of the genera-tor, and also to facilitate the handling of said supporting device. The supporting device is adapted to be mounted on the head member 14 of the generator.

From the rim of the annular part 40 of the supporting device there extends a'plurality of arms 42, one for each of the brush units. Said arms 42 are integral with or otherwise fixedly connected to the part 40 of the supporting device. Each of said arms 42 is provided with a bayonet slot 43 extending in from one side thereof, and the inner end of said slot is suitably located for proper coaction of the parts as will hereafter be more apparent.

At the outer end of each retractor member there is provided a shoulder 32 and a handle portion 33. The shoulder 32 is so located that when the rod 30 of a retractor member is inserted in one of the openings 16 in the end of the generator casing 15 and the bent over hook portion 31 at the inner end of said rod 30 is caused to engage the brush carrier arm 18, the rod 30 of the retractor member may then be inserted sidewise in the bayonet slot 43 and, when located at the inner end thereof, the shoulder 32 will serve to maintain the brush holder in proper position to cause the brush to be retracted outwardly whereby the brush will clear the surface of the commutator.

It should, of course, be understood that one of the retractor members is provided for each of the brush units, and that when all four of the brushes are retracted as aforesaid the armature may be removed from the casing without any danger of the brushes being impelled inwardly to positions where it would not be possible to replace the armature by reason of the brushes forming an obstruction to the reinsertion of the armature.

On the other hand, it repairs or adjustment are required only in connection with the brushes or their supporting or associated parts, the head member 14 may be removed from the end of the casing 15 in which the commutator is located. in this instance, the brushes may be left to be impelled inwardly by their springs after the head is removed with the brush assemblies carried thereby.

When, however, it is desired to replace the head member, with the brush assemblies carried thereby, the device of the present invention is placed in its operative relationship on the head member 14. The retractor members are then caused to engage the brush carrier arms 18 and the brushes 17 are retracted by mounting the retractor members in the arms 42 of the supporting device as aforesaid.

The head member 14 may now be partially replaced until the retractor members engage the end face of the casing 15 at which time the brushes which are held by the retractor members will be partially overlapping the end of the commutator, and the end of the armature shaft 12 will be within the bearing 13 provided in the head member 14. The retractor members may now be moved, which will permit the brushes to contact the commutator at the end portion thereof, whereby it will be possible, after removal of the retractor members, to push the head member to its final position on the end of the casing and thus cause the brushes to be properly located over the middle portion of the commutator.

It has been found that. in the use of the foregoing device the assembling of the generators and the like, used in automobile ignition systems, either initially or after repair, will be greatly expedited by reason of the facility afforded through the proper holding of the brushes in the retracted positions thereby to permit the parts to be quickly brought to their proper relationship.

I claim:

1. A brush retractor for use in the assembly of electrical generators and the like comprising, for each of the brush units, a separate manually operable retractor member having a hook portion for engaging a portion of the brush tholder, and a supporting device adapted to be mounted on the end plate of the generator housing, said supporting device having a plurality of arms each extending when said supporting device is in its operative position at a fixed radial distance from and substantially parallel to the axis of the generator armature, each of said arms having a slot therein for the reception of a retractor member, and each of the retractor members having a shoulder adapted to bear against the outer face of the and a supporting device adapted to be mounted on the end plate of the genera-tor housing, said supporting device having a plurality of arms each extending when said supporting device is in its operative position at a fixed radial distance from and substantially parallel to the axis of the generator armature, each of said arms having a slot therein for the reception of a retractor member, and each of the retractor members having a shoulder adapted to bear against the outer face of the arm of the supporting device, when the retractor member is in its operative position in the slot of said arm, thereby to hold the brushes in retracted positions cllear of the commutator of the generator armature.

3. A brush retractor for use in the assembly of electrical generators and the like comprising, for each of the brush units, a separate manually operable rctractor member comprising a rod having one end bent over to provide a hook for engaging a portion of the brush holder, and a supporting device adapted to be mounted on the end plate of the generator housing, said supporting device having a plurality of arms each extending when said supporting device is in its operative position at a fixed radial distance from and substantially parallel to the axis of the generator armature, each of said arms having a slot therein for the reception of a retractor member, and each of the retractor members having a shoulder adapted to bear against the outer face of the arm of the supporting device, when the retractor member is in its operative position in the slot of said arm, thereby to hold the brushes in retracted positions clear of the commutator of the generator armature.

4. A brush retractor for use in the assembly of electrical generators and the like comprising, for each of the brush units, a separate manuaflly operable retractor member comprising a rod having one end bent over to provide a hook for engaging a portion of the brush holder, and a supporting device adapted to be mounted on the end plate of the generator housing, said supporting device having a plurality of arms each extending when said supporting device is in its operative position at a fixed radial distance from and substantially parallel to the axis of the generator armature, each of said arms having a bayonet slot extending in from one side thereof for the reception of a portion of a retractor member, and each of the retractor members having a shoulder adapted to bear against the outer face of the arm of the supporting device, when the retractor member is in its operative position in the slot of said arm, thereby to hold the brushes in retracted positions clear of the commutator of the genera tor armature.

References Cited in the file of this patent UNITED STATES PATENTS 1,986,093 Abernathy Jan. 1, 1935 2,043,546 Koenig June 9, 1936 2,249,396 Riccio July 15, 1941 2,472,018 Johnson May 31, 1949 2,495,430 Stroburg Jan. 24, 1950 

